th Rudiger Wolfrum celebrated his 65 birthday on 13 December 2006. On this special occasion, current and former members of the large circle of his PhD and post-doctorate students (Doktoranden und Habilit- den) organized a symposium on the subject of International Law - day: New Challenges and the Need for Reform? to honour him and his academic work as a teacher and researcher. The symposium took place at the Max Planck Institute for Comparative Public Law and - ternational Law in Heidelberg on 15 and 16 December 2006. Since Rudiger Wolfrum is a renowned scholar in many different fields of...